Your saying that it could not be a different mother, but it could be a different person walking into the house and finding the drowning child. Can you tell me how that is relevant, though? If I tweak the scenario so that there is only you and the drowning child left in the world, then it could not be anybody else in the scenario, but the moral issue is exactly the same; you would be morally obliged to help the child and stop them from drowning.
Ah yes, I like this scenario better.
I agree with you that if I were alone in the universe with a drowning kid I would feel morally obliged to help him.
But that is also because the "cost" of saving him is negligible compared to the result.
What if the kid kept taking a bath every 5 minutes for the next "n" months and I had to be there to save him from drowning all the time?
I guess I would still be there to save him. Mainly because he/she is the other human left and the benefit of having company is worth sacrificing "n" months of my sanity.
But what if I were the only person who could watch some given kid to prevent him from drowning for those n months while the rest of humanity carries on with their life as normal... then I think I might let him die and join the rest of the world. His life would not be worth "n" months of my sanity, in that case.
But then again, it depends on how big "n" is.
1 week? It's definitely a sacrifice I would do.
1 month? Still doable.
3 months? Could be worth a sarcifice, depends on my life situation.
6 months? Not sure.
9 months? Eh, I think I would lose sanity.
10 years? No way! I let that little drowning idiot die ^_^
So I guess it all boils down on how long you have to "lend them your body" compared to how strong-willed you are and how much importance you place in "doing something else".
And if the fact that the child would not have existed if the mother did not exist, gives the right for the mother to take away the life of the child, why can't that principle be applied after birth aswell?
No, that alone doesn't give such right.
It's that PLUS being the only entity that is the common denominator to his existence.
Which, together, imply that the mother has to lend her body to the kid with continuity for 9 months for the kid to even begin existing.
So I think that the freedom and the health (physical and mental) of the "human incubator" (who, by being pregnant, has proved to be a fully functional individual capable of reproduction) has priority over the "incubated human" (who might or might not develop into a fully functional individual).